Such a bicycle handlebar is, e.g. known in the form of a racing-type handlebar. In the same, the upper handlebar grip portion is connected with the lower handlebar grip portion via a forwardly and downwardly extending curved member. At least two grip positions are, in principle, possible with this handlebar. In the case of the upper handlebar grip, the respective upper handlebar grip portion is grasped with the hands and in the case of the lower handlebar grip a corresponding portion of the lower handlebar grip is grasped.
In this known racing-type handlebar it is disadvantageous that the upper handlebar grip portion extending in straight fashion and in horizontal direction is only relatively poorly suited for an anatomically favourable posture of the hand. The forearm is inwardly twisted, as compared with a relaxed forearm position, so that the hand can grasp the upper handlebar grip. This is uncomfortable for the rider and tiring in the long run. Due to the twisting of the forearm, the muscles, in particular the biceps can furthermore not be used very well for bringing the forearm up to the upper arm upon the influence of force on the racing-type handlebar.
Due to the posture of the forearm, the elbows furthermore project out of the contour of the body, if the handlebar is subjected to pulling in order to exert pressure on the saddle and the pedals, which leads to worse aerodynamics.
It is furthermore of disadvantage that, in the case of a simultaneous attachment of an aero-type handlebar to the racing-type handlebar, which is normally fastened to the horizontal and straight upper handlebar grip portion, there is only little space between aero-type handlebar and racing-type handlebar, and the hands have consequently no space near the attachment.
It is furthermore of disadvantage in the lower handlebar grip that the body weight slightly bends the wrist inwardly. This leads to a high strain both of the wrist and of the hand itself. The sensation of numb fingers may even occur. In both grip positions the force arc for the force transmissions from the foot via the back to the hand is not effected in a line being as straight as possible, but via a partly bent line, and is thus disadvantageous.
In a further bicycle handlebar, the so-called horn-type handlebar, the upper handlebar grip portion extends in straight and horizontal fashion or in forwardly and downwardly inclined fashion. It is connected to the lower handlebar portion via a forwardly extending curved member. As opposed to the racing-type handlebar, the lower handlebar portion is disposed substantially in the same plane as the upper handlebar grip portion and does not really extend below the same. The lower handlebar portion extends in curved fashion forwardly and upwardly at the ends. The disadvantages in the upper handlebar grip correspond to that of the racing-type handlebar in the horn-type handlebar. It is similar with the lower handlebar grip, because the forwardly and upwardly projecting horns are grasped by the hands in the case of the same and lead substantially to the same problems as in the lower handlebar grip of the racing-type handlebar.